The invention relates to a system and method for evaluating quality of service in wireless communication system for voice traffic, data traffic, or both.
Since the introduction of cellular systems and other wireless communication systems, service providers have generally billed subscribers"" use of communication resources on a timed basis. Accordingly, a typical wireless communication system computes billing records based on call durations of subscribers.
One problem with billing solely based upon call duration is that subscribers may be billed for unusable time. Unusable time refers to any time during which the communication system does not function with sufficient reliability to meet an expected quality of service for one or more subscribers. For example, unusable time is present when a subscriber transiently passes through a dead-spot in radio frequency coverage and loses a portion of a conversation. Similarly, unusable time is present when interference degrades call quality so that a subscriber tries to communicate against a backdrop of static, noise, cross-talk, or garbled signals. Nevertheless, communication systems, which evaluate billing solely based upon call duration, often lack the capability to reduce or eliminate charges for unusable time, possibly leading to the loss of wireless customers.
Another problem with present wireless communication systems is that often only one quality standard of service is offered for a myriad of subscribers with divergent communication needs. Some subscribers with lower incomes or indifference to quality, may desire less expensive wireless communication services for voice traffic. For example, college students may desire low-tier voice wireless service, while executives may desire a high-tier or high-fidelity voice wireless service. Therefore, a need exists for a wireless communications system that supports billing records for different levels of voice quality service for subscribers.
Yet another problem of present wireless communication systems concerns reliability issues associated with wireless data applications. As potential data traffic applications proliferate on wireless communications systems, businesses may desire wireless data access with premium reliability. Data subscribers, who engage in data transmissions, may prove to be even more demanding of transmission quality than voice subscribers, who solely engage in voice transmissions. Therefore, a need exists for a wireless communications system that supports billing records for different levels of data quality service for subscribers.
Measuring quality of service on wireless communication systems presents unique challenges. The actual quality of service within a wireless communication system tends to fluctuate continually. Fluctuations may be caused by radio frequency propagation, subscriber movement, mobility management, limited radio resources, and fluctuating network conditions, among other factors. Maintaining a negotiated level of quality of service is difficult in such a dynamic quality of service environment. Thus, a need exists for a communication system featuring a quality of service evaluation that can reliably operate in a changeable quality of service environment.
In accordance with the invention, a communications system and method allows a system operator to establish a target quality of service level for a corresponding subscriber. The target quality of service is preferably selected from a hierarchy of standard quality of service levels. A subscriber may chose the target level of service appropriate for the subscriber""s communication requirements, such as voice requirements, data requirements, or even packet-data requirements. Communication system resources are expended to attempt to maintain the target quality, despite fluctuations in factors opposing maintenance of the target quality. An actual measured quality of service is evaluated for compliance to the established target quality of service. Because a billing record preferably reflects the actual measured quality of service, rather than call duration alone, customer satisfaction involving billing may be improved. Characterizing actual quality of service as noncompliant or compliant intervals permits objective identification and tracking of unusable time. The wireless communications system and method supports billing records for different levels of voice quality or data quality to accommodate divergent communication requirements of subscribers.
In a preferred embodiment, an accurate billing record may be generated even in a dynamic quality of service environment, because the communications system continuously or periodically measures both expended resources and actual performance for a corresponding subscriber. Even if the communication system fails to measure or inaccurately measures the actual performance associated with a subscriber, billing integrity is preserved through the measurement of expended resources as a dynamic indicator of the provided quality of service for the subscriber. The measurement of expended resources provides a baseline for comparison against the measured actual performance. Thus, the combined measurements of resource use data and system performance data during a common measuring interval for a subscriber enhance billing reliability and billing flexibility for wireless service providers.